The invention relates to a method and to a sensor for the detection of cavitations in accordance with the respective independent patent claim and to an apparatus containing a sensor of this kind.
By a cavitation one understands a sudden cavity formation such can arise for example when in liquid ring vacuum pumps--these are pumps which use a liquid as an auxiliary means for the production of a vacuum--the previously evaporated liquid condenses very rapidly or even abruptly. In liquid pumps of this kind a mechanical impact or striking on the blade or blades of the blade wheel between which the gas is located arises through a cavitation of this kind. This results in a more or less minor damage to the blades in each cavitation, through which the blade wheel and thus the pump becomes unusable with time.
Now it is often the case in industrial uses that the pumps are located at a place where they cannot be continually monitored without further ado as to whether and how often such cavitations arise. Moreover, the pumps also produce a certain operating noise during operation (even without cavitations occurring), which can at times be quite considerable, so that it can be difficult even in a monitoring of the pumps by the operating personnel to recognize whether and at what frequency such cavitations now arise.
Since on the other hand cavitations can lead to damage of the pump with time, as already explained above, such cavitations should be avoided or at least detected in order that corresponding measures can be taken (e.g. the operating parameters can be changed) in order to prevent a continuous arising of such cavitations.